Indeed, GPCR signaling and the pathways associated with it (GPCR ligand binding, G protein–coupled receptor signaling, GPCR downstream signaling, G-alpha signaling events, and cAMP-responsive element binding protein (CREB) signaling via PKC and MAPK) were among the pathways identified as enriched in m.CR compared with m.PR tumor cells by functional enrichment analysis (Fig. 1E; Supplementary Table S2). This evidence concerns the gene CREB1 and neoplasm.